1. Field Of The Invention
This invention relates to electronic float activated gauges which report information on the level of liquid in a tank.
2. Description Of The Art
Various types of float activated electronic gauges are known. Examples are U.S. Pat. No. 5,224,379 (a magnet affixed to a float moves vertically past a magnetic reed switch so as to turn on an indicator light); U.S. Pat. No. 2,405,140 (motion of a float causes rotation of a magnet, which in turn causes pivoting of an arm to light indicators); and U.S. Pat. No. 3,709,038 (float rotates a complex magnetic coupling).
While these prior art gauges each have their own advantages, it is desirable to provide a compact float gauge which minimizes the number of moving parts and the size of the magnet required, isolates the electric wiring from the fluid, reduces signal chattering in response to transient level changes, provides feedback at multiple different levels in the tank, and avoids the need for different wiring when larger tanks are used. Also, such a gauge should preferably be reliable in a high vibration environment (e.g. when used on a snowmobile gas tank). These goals should be achieved while keeping the costs of manufacturing and assembly of the gauge low. To date, no electronic float gauge has met all of these needs.